Information Technology Reference
In-Depth Information
roughly the same stu." She looked hurt. \Yes, but this is a rst cut; I would
expect to refactor those into a common set of classes when the structure is
clear." \But remember Ivor's presentation. He has exactly the same informa-
tion in his customer object already. You can just reference it." \But he has too
much information, and his names don't correspond to the way we look at the
process." Alex smiled. \Remember what I said earlier about correspondences.
You can refer to the classes in your design as being in an abstract package.
Then, if you have a correspondence with the information view that renames
and selects items as appropriate, the tools can construct the correct concrete
classes in your view for you, based on that linkage. You don't need to do it
all from scratch again."
Ivor scowled. \But then, if I change that part of my design, I might break
the computational view." \Certainly, it's possible," said Alex, \but when you
ask for a global check before committing, you would get a warning. However,
that should be rare, and if it happens, it probably means there is a shared
issue you should be discussing anyway. Without that linkage, you would still
be thinking about that common part of the design in different ways, but no
one would know."
Nigel waved his pencil in the air. \But that means that when the business
analysts have a bright idea and decide to add a video feature to customer
notifications, it ripples all the way down to the infrastructure, and the nightly
builds will break! That would be ridiculous." \Of course," said Alex. \That
would be silly. But what happens at the moment?" \Eleanor raises it in the
weekly meeting, Claire looks at the application implications and sends me
a memo, and I cost the deployment change with Trevor and Trudy. That's
generally the end of the matter." Everybody laughed, except Marcus. \And
we don't improve our market position," he growled.
\But hang on," said Alex, \you still have the version management to protect
you from any real damage. The business guys try the change, do a check, and
get a red flag. They can then start the consultation process; maybe Eleanor
starts a thread to discuss it, and everyone can contribute. You can all see the
branch with the new change in it and trace the flags it has generated in your
own view to see the consequences, so the resolution should be much quicker
and the results more reliable. In the end, you all win. And we can do the same
sort of thing with most of the other overlaps we have found this afternoon."
